Donald Trump stop in busy border city of San Diego sparks protest

Donald Trump brought his message of walls and deportations to the doorstep of America's busiest border crossing on Friday as the presumptive Republican presidential nominee greeted supporters in San Diego, amid one of the largest counter-protests organized against him.

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The scene inside the San Diego Convention Center during Trump's speech was relatively placid, while outside demonstrators opposed to his controversy-ridden White House bid marched and chanted, carrying signs criticizing his rhetoric against illegal immigration.

Waving U.S. and Mexican flags, more than 1,000 people turned out for anti-trump rally in San Diego, a city on the U.S.-Mexico border whose San Ysidro port of entry sees nearly 300,000 people a day cross legally between the countries.

San Diego is considered a binational city by many who live and work on opposite sides of the border, and about a third of the city's population is Latino. Some protesters on Friday afternoon attempted to breach a barrier manned by police, climbing over railings and throwing objects at officers, who used their night sticks in an attempt to hold back the crowd.

As clusters of Trump supporters and anti-Trump demonstrators began to mix following the candidate's appearance, police declared the gathering to be an unlawful assembly and ordered people to disperse. Police reported making at least three arrests.

Trump has weathered months of blowback from all ends of the political spectrum for his immigration policy, which calls for the building of a wall along the U.S.-Mexico border and deporting the nearly 11 million undocumented immigrants who reside in the United States.

Critics have said his plan is needlessly cruel and impossible to implement. At Trump's campaign stops, attendees often chant "build the wall."

Friday was not the first time Trump has been greeted by civil unrest in California, which is home to the largest Latino population in the country.

Late last month, a visit to the California Republican convention set off days of protests in the area, leading to several arrests.